1. Field of the Invention
The present invention relates generally to Ethernet systems and, more particularly, to a system and method for enhanced physical layer device autonegotiation.
2. Introduction
Ethernet devices continue to evolve in capability, including different transmission rates (e.g., 10 Mbit/s, 100 Mbit/s, 1 Gbit/s, 10 Gbit/s, etc.), different standards for those transmission rates (e.g., 100BASE-T2, 100BASE-T4, and 100BASE-TX for 100 Mbit/s over copper), and different duplex modes (i.e., half duplex and full duplex) within a standard. Ethernet devices can be designed to function with different sets of capabilities. Accordingly, a pair of Ethernet devices must communicate with a common set of capabilities to ensure interoperability.
In one configuration scenario, network administrators can manually set the speed and duplex mode of each network interface card. While this process can be effective in identifying the particular transmission capabilities used by all Ethernet devices in a plant, it is time consuming and prone to errors. Efficiency can be gained through the use of an autonegotiation process between a pair of Ethernet devices. This autonegotiation process has the potential to remove manual installation errors. However, autonegotiation is designed to identify a common set of transmission parameters for a single link, not a common set of transmission parameters for all Ethernet devices in a plant. Moreover, an autonegotiation process is typically defined only for a particular set of standardized transmission parameters. For example, the autonegotiation process is not designed to allow for negotiation between non-standard link rates. What is needed therefore is a mechanism that addresses the deficiencies of current autonegotiation processes in accommodating network configuration efforts and ever-evolving Ethernet transmission technologies.